<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		.red {
			color: red;
		}
		li:nth-child(2) {
			color: #00ff00;
		}
		#rgb {
			color: rgb(0,0,255);
		}
		
	</style>
</head>
<body>
	<h3>文本的颜色</h3>
	<ol>
		<li class="red">一种</li>
		<li>二种</li>
		<li id="rgb">三种</li>
	</ol>
</body>
</html>